Alinco DR-235T, DR-235T MKII and DR-235T MKIII
Expanded RX/TX
Turn the radio off. Disconnect the power source. Open the bottom cover by
removing the 4 screws located on each corner of the bottom cover surface.
Locate a BLUE looped jumper wire that comes out of a slot on the back of
the front control unit (it is attached to the back of the front panel on a pad).
Remove the jumper and trim the remaining wire properly to prevent a short circuit.
Reassemble the bottom cover. Connect the power source and turn on the unit
with the FUNC key pressed to reset the microprocessor. Settings will become the
factory default.
The unit will transmit and receive between 200.000 and 299.999 MHz where the VCO
locks. If the display is flashing, you have lost VCO lock and operation is not
possible. If you need coverage far outside the US ham band of 222-225 MHz, you
will have to re-align the VCO. The procedure is as follows:
1: In RX, tune to the highest needed QRG. Adjust L503 so that PD voltage is 2.2 V
2: In TX, tune down 10 KHz and confirm that PD voltage is less than 6.2 V
L503 is located inside the shielded box on the main unit.
PD measuring point is right next to the shielded box, clearly marked on the PCB.
Please note that VCO bandwidth for TX and RX differs. Also, it may not be possible
to align the VCO to any given segment of 200-299.995 MHz without further modification
of the VCO circuit. And last but not least; if you plan to use a large duplex shift
for link operation, you'd better tune somewhere in between the two QRG's needed
in step 1 above.
Bonus:
If you press the FUNC key and the SQL key when you turn the power on you will get
a handy digital voltage display.